When I hit sand on a descent (which is every descent here), I make sure to modulate my brakes if I use them at all. If I am using any brakes, it's the front mostly but if the rear starts to skid and make that shsss sound, I release the front brake and pick up speed. That will pull the rear end back in line, providing it's not too far gone. I keep my weight back too.
Relax, enjoy the ride. The trail isn't going anywhere.
Tzvia- rollin' slow...
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